They told the court that a semen-stained mattress and pillow taken from an apartment where Mr Anwar allegedly had trysts with the wife of his private secretary would be produced in court on Tuesday.

Mr Anwar is accused of illegal sexual acts, and of coercing retractions from two people who made sexual allegations against him - charges he says are politically motivated.

Amid gasps from the public gallery, Assistant Commissioner of Police Musa Hassan Musa said tests on the mattress and pillow were being carried out by government scientists to determine if they matched samples from Mr Anwar.

"The mattress is now in the chemists' department," a prosecution lawyer told the court. "We hope to bring it to court tomorrow."

Mr Musa said the bedding was found in a flat belonging to a company associated with Mr Anwar's tennis partner Solaimalai Nallakaruppan.

Trysts alleged

Wan Azizah Wan Ismail: Listened calmly to new evidence

He said the police were investigating claims that Mr Solaimalai had helped to arrange meetings in the flat involving Mr Anwar and Shamsidah Mohamad Tahrin - the wife of Mr Anwar's secretary, Azmin Mohamad Ali.

Mr Musa said the claims had emerged in a book entitled Fifty reasons why Anwar cannot be prime minister. The accusations prompted an investigation earlier this year, before Mr Anwar was sacked from his post as deputy by Prime Minister Mahathir Mohamad.

Mr Anwar scribbled notes throughout the testimony. His wife Wan Azizah Wan Ismail, who was with him in court, listened impassively.